Legends

Legend Quickstart

Many plottables have a Label property that can be set so they appear in the legend.

ScottPlot.Plot myPlot = new();

var sig1 = myPlot.Add.Signal(Generate.Sin(51));
sig1.LegendText = "Sin";

var sig2 = myPlot.Add.Signal(Generate.Cos(51));
sig2.LegendText = "Cos";

myPlot.ShowLegend();

myPlot.SavePng("demo.png", 400, 300);

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Right To Left (RTL) text support

Enabling Right To Left (RTL) support correctly renders text in RTL languages.

Legend.cs

ScottPlot.Plot myPlot = new();

LabelStyle.RTLSupport = true; // enable right-to-left text support

var sig1 = myPlot.Add.Signal(Generate.Sin(51));
sig1.LegendText = "אמת"; // example right-to-left text

var sig2 = myPlot.Add.Signal(Generate.Cos(51));
sig2.LegendText = "English"; // example left-to-right text

myPlot.ShowLegend();

myPlot.SavePng("demo.png", 400, 300);

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Manual Legend Items

Legends may be constructed manually and markers customized.

Legend.cs

ScottPlot.Plot myPlot = new();

myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
myPlot.Legend.IsVisible = true;

LegendItem item1 = new()
{
    LineColor = Colors.Magenta,
    MarkerFillColor = Colors.Magenta,
    MarkerLineColor = Colors.Magenta,
    MarkerShape = MarkerShape.Cross,
    LineWidth = 2,
    LabelText = "Alpha"
};

LegendItem item2 = new()
{
    LineColor = Colors.Green,
    MarkerFillColor = Colors.Green,
    MarkerLineColor = Colors.Green,
    LineWidth = 4,
    LabelText = "Beta"
};

LegendItem[] items = { item1, item2 };
myPlot.ShowLegend(items);

myPlot.SavePng("demo.png", 400, 300);

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Legend Customization

Access the Legend object directly for advanced customization options.

Legend.cs

ScottPlot.Plot myPlot = new();

var sig1 = myPlot.Add.Signal(Generate.Sin(51));
sig1.LegendText = "Sin";

var sig2 = myPlot.Add.Signal(Generate.Cos(51));
sig2.LegendText = "Cos";

myPlot.Legend.IsVisible = true;
myPlot.Legend.Alignment = Alignment.UpperCenter;

myPlot.Legend.OutlineColor = Colors.Navy;
myPlot.Legend.OutlineWidth = 5;
myPlot.Legend.BackgroundColor = Colors.LightBlue;

myPlot.Legend.ShadowColor = Colors.Blue.WithOpacity(.2);
myPlot.Legend.ShadowOffset = new(10, 10);

myPlot.Legend.FontSize = 22;
myPlot.Legend.FontName = Fonts.Serif;

myPlot.SavePng("demo.png", 400, 300);

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Legend Marker Shape Override

Use the legend shape override to force all legend items to display using the given marker shape.

Legend.cs

ScottPlot.Plot myPlot = new();

// this shape will be used for legend items without defined markers
myPlot.Legend.MarkerShapeOverride = MarkerShape.FilledCircle;

var sig1 = myPlot.Add.Signal(Generate.Sin(51));
sig1.LegendText = "Sin";

var sig2 = myPlot.Add.Signal(Generate.Cos(51));
sig2.LegendText = "Cos";

LegendItem item1 = new()
{
    MarkerColor = Colors.Red,
    MarkerShape = MarkerShape.Cross,
    LabelText = "Alpha"
};

LegendItem item2 = new()
{
    MarkerColor = Colors.Green,
    MarkerShape = MarkerShape.FilledSquare,
    LabelText = "Beta"
};

myPlot.Legend.ManualItems.Add(item1);
myPlot.Legend.ManualItems.Add(item2);

myPlot.ShowLegend();

myPlot.SavePng("demo.png", 400, 300);

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Legend Marker Shape Override with auto color

Use the legend shape override to force all legend items to display using the given marker shape. Color is determined automatically in this example.

Legend.cs

ScottPlot.Plot myPlot = new();

List<PieSlice> slices =
[
    new PieSlice() { Value = 5, FillColor = Colors.Red, Label = "Red", LegendText = "R" },
    new PieSlice() { Value = 2, FillColor = Colors.Orange, Label = "Orange" },
    new PieSlice() { Value = 8, FillColor = Colors.Gold, Label = "Yellow" },
    new PieSlice() { Value = 4, FillColor = Colors.Green, Label = "Green", LegendText = "G" },
    new PieSlice() { Value = 8, FillColor = Colors.Blue, Label = "Blue", LegendText = "B" },
];

myPlot.Legend.MarkerShapeOverride = MarkerShape.FilledCircle;

var pie = myPlot.Add.Pie(slices);

myPlot.Axes.Frameless();
myPlot.HideGrid();
myPlot.ShowLegend();

myPlot.SavePng("demo.png", 400, 300);

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Legend Orientation

Legend items may be arranged horizontally instead of vertically

Legend.cs

ScottPlot.Plot myPlot = new();

var sig1 = myPlot.Add.Signal(Generate.Sin(51, phase: .2));
var sig2 = myPlot.Add.Signal(Generate.Sin(51, phase: .4));
var sig3 = myPlot.Add.Signal(Generate.Sin(51, phase: .6));

sig1.LegendText = "Signal 1";
sig2.LegendText = "Signal 2";
sig3.LegendText = "Signal 3";

myPlot.ShowLegend(Alignment.UpperLeft, Orientation.Horizontal);

myPlot.SavePng("demo.png", 400, 300);

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Legend Wrapping

Legend items may wrap to improve display for a large number of items

Legend.cs

ScottPlot.Plot myPlot = new();

for (int i = 1; i <= 10; i++)
{
    double[] data = Generate.Sin(51, phase: .02 * i);
    var sig = myPlot.Add.Signal(data);
    sig.LegendText = $"#{i}";
}

myPlot.Legend.IsVisible = true;
myPlot.Legend.Orientation = Orientation.Horizontal;

myPlot.SavePng("demo.png", 400, 300);

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Multiple Legends

Multiple legends may be added to a plot

Legend.cs

ScottPlot.Plot myPlot = new();

for (int i = 1; i <= 5; i++)
{
    double[] data = Generate.Sin(51, phase: .02 * i);
    var sig = myPlot.Add.Signal(data);
    sig.LegendText = $"Signal #{i}";
    sig.LineWidth = 2;
}

// default legend
var leg1 = myPlot.ShowLegend();
leg1.Alignment = Alignment.LowerRight;
leg1.Orientation = Orientation.Vertical;

// additional legend
var leg2 = myPlot.Add.Legend();
leg2.Alignment = Alignment.UpperCenter;
leg2.Orientation = Orientation.Horizontal;

myPlot.SavePng("demo.png", 400, 300);

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Legend Outside the Plot

Use the ShowLegend() overload that accepts an Edge to display the legend outside the data area.

Legend.cs

ScottPlot.Plot myPlot = new();

var sig1 = myPlot.Add.Signal(Generate.Sin());
var sig2 = myPlot.Add.Signal(Generate.Cos());

sig1.LegendText = "Sine";
sig2.LegendText = "Cosine";

myPlot.ShowLegend(Edge.Right);

myPlot.SavePng("demo.png", 400, 300);

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Automatic Legend Items Custom Font

Use custom fonts from TTF files in the legend.

Legend.cs

ScottPlot.Plot myPlot = new();

Fonts.AddFontFile("Alumni Sans", Path.Combine(GetFontsBasePath(), @"AlumniSans/AlumniSans-Regular.ttf"), bold: false, italic: false);

var sig1 = myPlot.Add.Signal(Generate.Sin(51));
sig1.LegendText = "Sin";

var sig2 = myPlot.Add.Signal(Generate.Cos(51));
sig2.LegendText = "Cos";

myPlot.Legend.FontName = "Alumni Sans";
myPlot.Legend.FontSize = 48;
myPlot.Legend.FontColor = Colors.Red;

myPlot.ShowLegend();

myPlot.SavePng("demo.png", 400, 300);

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Manual Legend Items Custom Font

Use custom fonts from TTF files in the legend (manual legend items).

Legend.cs

ScottPlot.Plot myPlot = new();

// Add a font file to use its typeface for fonts with a given name
Fonts.AddFontFile(
    name: "Alumni Sans",
    path: Path.Combine(Paths.FontFolder, @"AlumniSans/AlumniSans-Regular.ttf"));

var sig1 = myPlot.Add.Signal(Generate.Sin(51));
sig1.LegendText = "Sin";

var sig2 = myPlot.Add.Signal(Generate.Cos(51));
sig2.LegendText = "Cos";

myPlot.Legend.ManualItems.Add(new LegendItem()
{
    LabelText = "Custom",
    LabelFontName = "Alumni Sans",
    LabelFontSize = 18,
    LabelFontColor = Colors.Magenta,
    LinePattern = LinePattern.Dotted,
    LineWidth = 2,
    LineColor = Colors.Magenta,
});

myPlot.SavePng("demo.png", 400, 300);

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Legend with Title

Place a manual legend item at the top of the list and style it as desired to achieve a title inside the legend area.

Legend.cs

ScottPlot.Plot myPlot = new();

var sig1 = myPlot.Add.Signal(Generate.Sin(51));
sig1.LegendText = "Sine Wave";

var sig2 = myPlot.Add.Signal(Generate.Cos(51));
sig2.LegendText = "Cosine Wave";

var sig3 = myPlot.Add.Signal(Generate.Sin(51, 2));
sig3.LegendText = "High Frequency";

LegendItem legendTitle = new()
{
    LabelText = "Math Functions",
    LabelFontSize = 14,
    LabelFontColor = Colors.Navy,
    LabelBold = true,
    LabelOffsetX = -20, // compensate for space used to display shape
};

myPlot.Legend.ManualItems.Add(legendTitle);

myPlot.SavePng("demo.png", 400, 300);

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